Packing means for rotary pumps



March 18 1924. 1,487,567

- E. HILL Y PACKING MEANS FOR-ROTARY PUMPS Filed May 1, 1925 2 Sheets-Sheet 1' IN VEN TOR A TTORNEY March 18 1924.

HILL

PACKING MEANS FOR ROTARY PUMPS Filed May 1, 1925 2 Sheets-Sheet 2 Z? INIVENTOR By M M$Wm ATTORNEY Patented Mar. 18, 1924.

.UNETED STATES assa. ATENT' FFME.

nnnnnznn HILL, or sou'rn noawnx, connnc'rrcur, assranon 'ro THE HILL comranssoa a some courm, or new ou, N. Y., a coaroaarron or nnmwimn raoxme mmns roe. ROTARY Poms.

Application filed Kay 1,

To aZZwiwm z't'ma concern:

Be it known that IyEBENEZER HILL, a

citizen of the United States, residing at South Norwalk, in the county of Fairfield and State of Connecticut, have invented a new and useful Improvement in Packing Means for Rotary Pumps, of which the following is a specification.

This invention relates to a rotary pump, in compressor, or similar apparatus hereinafter termed pump, for compressing or exhausting fluids, and more particularly fluids having dangerous or destructive properties.

The object of the invention is to so con- 16 struct the apparatus that the pumping can be continuously carried on with safety and without material injury to the wearing parts.

To this end the pump has a pumping so member rotating in a closed pumpin chamber within the .casing and a suitab e bearing for the pumping member located exteriorly to the pumping chamber either within the casing or outside of it, as the design of the apparatus may require. For preventing leakage to and from the umping chamber, the rotor which may be either the pumping member, or its hub, or the driving shaft, is provided with an automatically expansible packing means interposed between the pumping chamber and the bearing, said means consisting oil a rotatable packing member, a co-operating non-rotatab e packing member, and a resilient element arranged to form a gas tight connection between one of the packing members and the casing and confine any leakage to or from the pumping chamber to a leakage cavity. The resilient element is so constructed and arranged that the ressure of any leakage is utilized to force t e packing members into tight sealing engagement, which sealing engagement is consequently directly proportional to the pressure on opposite sides of the resilient element and this maintains a uniform sealing engagement around the entire circumference of the contacting surfaces of the packing members.

Lubricant can be introduced into the leakage cavity for the purpose of effecting a liquid seal and preventing the compressed fluid from coming into contact with the engagin surfaces of the packing members, if desire In the drawings Fig. 1 shows a longitudi- 1923. Serial No. 885,952.

nal section of a pump having the main hearng for the rotor eontained within the easmg and the packing interposed according to th1s invention between the bearing and the pumping chamber. Fig. 2 is a similar section of a pump with the main bearing mounted in a frame exterior to the casing.

The pump may be of any usual or approved type, comprising one or more rotary pumping members and the main bearing for the rotor or rotors may be located within the casing or may be located exterior thereto, but in every case, the main bearing 1s exterior to the pressure chamber, so that there will be no possibility of the compressed fluid comin into contact with the bearing or leaking t erethrough when the apparatus is in operation. This is particularly essent al in pumps employed for the compres- S1011 of explosive, inflammable, or corrosive gases, such as oxygen, hydrogen, acetylene, I ammonia, chlorine, etc, as otherwise damage is liable to occur. Further, this construction permits of a lubricant being used in the pressure chamber which is not harmful to, and which has no reaction with, the gas being compressed, and it also permits of a lubricant being used in the bearing which could not otherwise be used with safety.

In the preferred construction illustrated the pump casing 5 is cylindrical and has a head 6 secured to it in such manner that it may be removed to give access to the interior of the casing. The head has a hub 8 in which is mounted the journal 9 of the arbor 10 for the inner pumping member 11. Surrounding and oo-acting with the inner pumping member 11 is the outer pumping member 12, the perimeter of which fits snugly but rotatably in the casing 5.

The inner face of the head 6 is in contact with the adjacent faces of the pumping members 11 and 12, and in conjunction with those members and the casing 5 forms a pumping chamber in which the compression 1% or exhaustion of the gases is efiected, the outer pumping member 12 for this pur ose having a closed side 13. As shown in ig.

1', a hub 14 extends axially from the side 13 of the outer pumping member in a direc- 105 tion opposite from the head 6 and entered in the bore of the hub is. the actuating shaft 15 which rotates. the outer member 12.

Within the casing 5 are bearings 16 and mounted in, these bearingsis the hub 14. 9

The bearings as shown in Fig. 1 are exterior to the pumping chamber and separated from it by a leaka cavit in which the packing hereinafter escribe is contained.

To prevent the inward displacement of the bearing 16 the inner wall of the casing 5 is formed with an annular shoulder 17 opposed to the adjacent face of the bearing, and between this shoulder and the beari is a ring 30. Encircling the hub 14 on the outer side of the bearing 16 isthe stufling box 18 for the lubricant retaining placking ring 19. This stufling box 18, whic is secured in place by bolts 26, engages the bearing 16 and forces it inward. On the hub 14, preferably in juxtaposition to the back of the outer pumping member is a fillet 21, which may be either an integral part of the rotatory part or may be a separately made ring shrunk gas tight on the hub. This fillet which is shown with a curved face acts as the rotatable packing member employed to prevent the escape of fluid to or from the pumping chamber. Encircling the fillet is a ring 22 having a contacting surface correspondingly shaped to that of the fillet and establishing a sealing engagement therewith= This ring acts as the non-rotatable packing member.

One extremity of the gas tight resilient packing element, shown in the form of a bellows 23, is welded, brazed, or otherwise tightly connected or anchored to the packing member 22 and the other end of this expansible member is brazed, welded or otherwise connected to the ring 30 that is anchored between the shoulder 17 on the casing and the bearing 16. The pressure exerted on the stuiiing box 18 and bearing 16 by the bolts 20 causes the bearing 16 to clamp the ring 30 against the shoulder 17 and establish a gas tight joint between the packing and the casing. This construction provides a leakage cavity 24 at the back of the outer pumping member 12 and shuts oif all communication between the leakage cavity and the bearing so that angel fluid escaping from the pumping cham r through the working clearance between the pumping members and the casing will be prevented from reaching the bearing 16 and from escaping from the apparatus at this side of the casing.

The packing element 23 consists in the case iliustrated of a corrugated resilient metallic tube and should any fluid leak from the pumping chamber to the leakage cavity its pressure would tend to spread the convolutions of this member and extend it. Such an expansion of the acki element 23 will force the non-rotata le pac 'ng ring 22 toward the rotatable fillet 21 and increase the force of the sealing engagement of these packing members= lVhen the apparatus is employed for vacuum work it is necessary to prevent leakage from the atmosphere to the pumping chamber. For such uses the apparatus is provided with the described packing but instead of the cavity receiving leakage from the pumping chamber the atmospheric ressure being greater on the outside 0 the resilient element causes the ex ansion of that member, and the forcing of the rotatable and non-rotatable packin members together as previously describe In Fig. 1 the rotor is assumed to be the rotatable pumpi member and its hub in which the actuating shaft is entered. In the form shown in Fig. 2 the pumpi member is constructed without a hub, aii the actuating shaft 25 is secured directly to it. In this construction the rotary packing member 21 may be either integral with or applied to the shaft and it may beeitherin juxtaposition to the pumping member or spaced therefrom. The stationary packing member 22 and the resilient packing element 23 in this form are as previously described, but the outer extremity of the expansible packing element 23 is fastened to the ring 30 which is clamped between the shoulder 17 and the stufling box 18. In the second form illustrated the shaft bearing 31 is independent of the pump casing.

The term rotor as used throughout the specification is to be understood to include within its meaning the rotatable pumping member or its hub or the driving shaft, and it is to be understood that the packing can be assembled with any one or all of these If the pump provided with a packing similar to that described is being used for pumping inflammable, explosive or otherwise dangerous or obnoxious gas, it is impossible for such gas, if there should be any leakage around the pum ing elements, to escape further than the lea age cavity where no damage would result. This is particularly so if the leakage cavity is filled with lubricating or packing fluid which substance may be such as will not dilute or injuriously affect the gas being pumped. The main bearings of the pumping element are protected by this form of packing against the deleterious action of corrosive gas being pumped and furthermore the bearings may be lubricated with suitable material that would form an explosive mixture or deleteriously affect the gas being pumped for the bearing lubricant is effectually shut oif from the pumpin chamber by the packing which is kept tig t regardless of wear according to the degree of difference in pressure on the inside and outside of the pac 'ng.

The invention claimed is 1. A rotary pump comprisin a casing having a pumping chamber an a leakage cavity communicating with the pumpin chamber, a rotor rotatably fitting sai chamber and closing one end of the leakage cavity, a bearing for the rotor exterior to the pumping chamber and leakage cavity, and an expansible packing interposed and forming a wall between the leakage cavity and the bearing whereby fluid pressure leaking from the pumping chamber to the leakage cavit is prevented from escaping through t e bearing and is caused to exert pressure against the back of the rotor.

2. A rotary pump comprisin a casing having a pumping chamber and a leakage cavity communicating with the umping chamber, a rotor rotatably fittin sa1d chamher and closing one end of the leakage cavity, a bearing for the rotor exterior to the pumping chamber and leakage cavity, and an expansible packing inter osed and forming a wall between the lea age cavity and the bearing whereby fluid pressure leaking from the pumping chamber to the leakage cavity is prevented from escaping through the bearing and is caused to force the rotor forward to reduce leakage from the pumping chamber to the leakage cavity.

3. A rotary pump comprising a casing having a pumping chamber and a leakage cavity communicating with the umping chamber, a rotor rotatably fitting sa1d chamber and closing one end of the eakage cavity, a bearing for the rotor exterior to the pumping chamber and leakage cavity, and an expansible packing having rotatable and stationary contacting members, interposed and forming a wall between the leakage cav ity and the bearing whereby fluid pressure leaking from the pumping chamber to the leaka e cavity forces said contacting members into sealing en agement and presses against the back of t e rotor with a force dependent upon the difierence in pressure on opposite sides of said packing.

4', rotary pump comprisinf a casing having a pumping chamber an a leakage cavity communicating with the umping chamber, a rotor rotatably fitting sa1d chamher and closing one end of the eakage cavity, a bearing for the rotor exterior to the pumping chamber and leakage cavity, and a packing consisting of a fillet on the rotor, a packin ring en aged with the fillet, and a gas ti t expansi le sleeve, connected with the pac 'ng tin and casing, said packing interposed and ormin a wall between the leakage cavity and the aring whereby fluid pressure leaking from the pumpin chamber to the leakage cavity is prevente from escaping through the bearin and is caused to exert pressure against t e back of the rotor.

5. A rotary pump comprising a casing having a pumping chamber and a cavity adapted to receive ubricating material communicating with the pum mg chamber, a rotor rotatably fitting said chamber and closing one end of said cavity, and an expansible packing interposed and forming one wall of the leakage chamber whereby fluid pressure leaking from the pumpin chamber to the leakage chamber is can d to exert pressure a amst the back of the rotor and to force In ricant from said cavity 7. A rotary pump comprisin a casing having a pumpmg chamber an a leakage cavity communicating with the pumping chamber, a rotor rotatably fittin sa1d chamher and closing one end of the leakage cavity and an ex ansible acking comprising a fillet rotatab e with t e rotor, a stationary rin fitted to said fillet, and a corrugated s eeve fitted gas tight to said ring and to the casing, said packin forming a wall of the leakage cavity w ereb fluid pressure leaking from the pumping c amber to the leakage cavity is confined and causedto exert pressure against the back of the rotor.

. 8. A rotary pump comprisin a casing having a pumping chamber an a leakage cavity communicating with the umping chamber, a rotor rotatably fitting sa1d chamber and closing one end ofthe eakage cavity, and an expansible packing sleeve forming a wall of the leakage cavitg', said packing sealing the cavity back of t e rotor with a pressure dependent on the difference of pressure on opposite sides of the acking.

. EBENEZER L. 

